AzureStorageKeyDetector scan multi lines and skip public keys

[anatolii-paloaltonetworks]

• Please check if the PR fulfills these requirements

• Tests for the changes have been added

• Docs have been added / updated

• All CI checks are green

• What kind of change does this PR introduce?
  Update azure_storage_key plugin to skip public keys and scan multiline if key and value are located in different lines

• What is the current behavior?

detected secret in public key (single line)

SshPublicKeys: ssh-rsa lJzRc1YdHaAA2KCNJJ1tkYwF/+mKK6Ygw0NGe170Xu592euJv2wYUtBlV8z+qnlcNQSnIYVTkLWntUO1F8j8rQ=="

detected secret in public key (multi line)

SshPublicKeys: 
- >-
ssh-rsa lJzRc1YdHaAA2KCNJJ1tkYwF/+mKK6Ygw0NGe170Xu592euJv2wYUtBlV8z+qnlcNQSnIYVTkLWntUO1F8j8rQ=="

• What is the new behavior (if this is a feature change)?

NOT detected secret in public key (single line)

SshPublicKeys: ssh-rsa lJzRc1YdHaAA2KCNJJ1tkYwF/+mKK6Ygw0NGe170Xu592euJv2wYUtBlV8z+qnlcNQSnIYVTkLWntUO1F8j8rQ=="

NOT detected secret in public key (multi line)

SshPublicKeys: 
- >-
ssh-rsa lJzRc1YdHaAA2KCNJJ1tkYwF/+mKK6Ygw0NGe170Xu592euJv2wYUtBlV8z+qnlcNQSnIYVTkLWntUO1F8j8rQ=="

• Does this PR introduce a breaking change?
  nothing

• Other information: